Liquid transporting tanks



D. S. BROWN LIQUID TRANSPORTING TANKS Aug. 2, 1955 2 Sheets-Sheet lOriginal Filed Oct. 14

Aug. 2, 1955 D. 5. BROWN LIQUID TRANSPORTING TANKS 2 Shee ts-Sheet 2 Original Filed Oct. 14, 1948 United States Patent LIQUID TRANSPORTINGTANKS David S. Brown, Fanwood, N. J. Continuation of application SerialNo. 54,376, ()ctoher 14, 1948. This application February 3, 1955, SerialNo. 485,981

9 Claims. (Cl. 280-) This invention relates to portable tanks in whichfluids, such, for example, as milk, are transported over high- *ways orrailroads and a general object of the invention is so to improve theconstruction of such tanks, particularly those designed to carryperishable products such as milk, that the pay load proportion of theoverall weight of the transported tank and contents will be increased.This application is a continuation of my copending application SerialNo. 54,376 filed October 14, 1948, now abandoned.

Because of increasing labor costs and the low maximum weights permittedon the highways of various States, the cost of shipping fluid products,such, for example, as milk, in overthe-road equipment has become aconsiderable part of the cost of the delivered product. A particularobject of the so to redesign the construction of tanks, particularlyinsulated tanks such as are used in transporting milk over highways orrailroads, that the weight of the tank may be very materially reducedwithout reducing its structural strength or its insulating efllciency,whereby the amount of pay load, that is, the amount of fluid carried atthe same labor cost and with the same overall weight of tank andcontents, may be materially increased.

In all conventional insulated liquid carrying tanks now in use the ingpart of the total structure. The outside jacket is merely a covering forholding and protecting the insulation which surrounds the insideliquid-holding tank.

I have discovered that, by taking advantage of the structuralcharacteristics of certain forms of insulation which are now upon themarket, a tank construction may be produced, which is of substantiallythe same structural strength as existing tanks and of greatly reducedweight, by making the inner and outer walls of the tank and theinsulation in the form of a substantially integral structure so thatboth of the tank walls and the insulation therebetween constitutefunctional parts of the weight-carrying structure of the tank.

With the foregoing and other objects in view the invention is hereinshown as embodied in a tank in which relatively light layers of suitablesheet metal are cemented to the two sides of a lightweight insulatingcore material which is of suftlcient inherent structural strength toproduce a resultant section of l-beam type. Effective adhesives orcements have been developed in recent years which will so secure themetal to the insulation as to produce substantially an integralstructure, so that the weight of the tank contents is carried by thestructure as a whole and reliance is not placed, as at present, onlyupon the weight supporting and distortion resisting strength of thatwall with which the liquid comes into contact.

In the accompanying drawing:

Figure l is a longitudinal sectional view through a tank, intendedprimarily for the transportation of perishable liquids, such as milk,over highways or railroads, in which the present invention has beenembodied.

present invention, therefore, is

inside tank structure is the weight-carryby the Minnesota Mining &

Fig. 2 is an enlarged sectional detail of a portion of the tank shown inFig. 1.

Fig. 3 is a transverse section on the line 3-3 of Fig. 1; and

Fig. 4 is a further enlarged, sectional detail of one of the reinforcingribs and the frame support therefor, this view showing particularly theconnections between the parts.

In the illustrative embodiment of the invention, the inner cylindricalwall 2 and the inner end walls 4 and 6 of the tank, may be made of arelatively thin layer of stainless steel or metal of equivalent utilityfor the purpose, effectively secured or bonded by any suitable adhesive8, such, for example, as a cement manufactured Mfg. Co., and designatedE. C. 524, to a core 10 of insulating material having considerableinherent structural strength, such, for example, as the material soldunder the trade name of Rubatex. Hot asphalt may also be used to bondthe metal and insulation layers together. If stainless steel be used forthe inner wall 2 and end walls 4 and 6 of the tank, it may be of athinness of 18 gauge for a tank of average capacity, say 3500 gallons.The outer wall 12 of the elliptical main body of the tank and the endwalls 14 and 16 may be made of the same material and of the same gaugeof material as the inner wall 2, or these walls may be made of othersuitable lightweight material, likewise effectively secured to the core16 of insulation by any suitable cement 8 so that the compositestructure, comprising the two metal walls and the insulating core, formsa substantially integral structural member sur'hciently strong tosupport the weight of the liquid in the tank and to withstand thestresses to which it is subjected in transportation over highways orrailroads.

As shown particularly in Fig. 3, the tank may be of the usual ellipticalsection, although the particular sectional shape of the tank is not anessential feature of the invention. Preferably stress rings 18, shapedto help maintain the section of the tank and securely fastened to boththe inner shell 2 and the outer shell 12, are provided, these ringsbeing in the form of laterally flanged channels, as shown moreparticularly in Figs. 2 and 4. The flanges 29 of the stress rings 13 maybe secured to the outer shell 12 of the main body of the tank by weldingthereto as shown at 22 before the insulating core 10 is placed therein.Preferably each channel is also filled with like insulation as shown at24. The inner shell 2 of the main body of the tank is preferablyprovided with countersunk openings 26 through which rivets 28 may bespot-welded to the bottoms of the channel rings 18, thus firmlyattaching the inner shell 2 to these rings. The tank as a whole may besupported on suitable trans verse supports such as the channels 30having their upper flanges 32 welded to the outer shell 12, as shown at34, or otherwise secured thereto.

As above suggested, in one embodiment of the invention the inner andouter shells 2 and 12 may be made of stainless steel, or the outer shell12 may be made of lightweight metal, such as aluminum or magnesium, of aconsiderably heavier gauge, in which case the structural strength mightbe so increased without increase of weight, as to permit the eliminationof the stress rings 18. Further structural strength might also beobtained by interposing between either one or both of the metal layersand the core of insulation 10, a layer of plywood, thoroughly bondedboth to the core 10 and the metal shell.

From an inspection of the drawings, it will be seen that the transversesupports 30 extend between reach bars 36 and that the reach bars 36extend substantially from end to end of the tank. Therefore, thesubstantially integral structural member which constitutes the improvedtank construction and which in itself is strong 3 enough to resistdeformation between its ends, these tanks being normally supported neartheir ends over the vehicular wheels, has also the advantage ofadditional support substantially throughout its length on the continuousreach bars 36.

It will further be noted that the flanges 38 of the reach bars 36 areshaped to conform substantially to the surface of the jacket 12 withwhich they contact, thus providing additional support for the tank. i

From the foregoing description it will be seen that the presentinvention makes possible the provision of a portable tank fortransmitting liquids, such as milk, over highways and railways which,for the same capacity, may be made of considerably lighter weightwithout any loss of weight-carrying strength or structural resistance tothe stresses to which it is subjected while being transported overhighways or railways. In fact, the invention has made possible theprovision of a tank of equivalent capacity which not only is of lighterweight, but in most cases is of considerably increased weight-carryingstrength and has considerably increased resistance to distortion due tothe stresses incident to transportation over the highways and railways.

Having thus described the invention what is claimed as new and desiredto be secured by Letters Patent is:

1. In a tank truck or trailer for use in transporting perishable liquidsover highways and in which an elongated tank is designed for supportnear its ends over the vehicular wheels, the combination with laterallyspaced reach bars extending approximately from end to end of 9 saidtank, of a tank comprising an inner liquid container of suitablecorrosion-resisting metal and an outer metal jacket, too thin toconstitute weight-carrying structural elements in themselves, and alayer of insulating material of substantial. inherent structuralstrength located between and so initimately bonded to the metal layersthat the three layers form a substantially integral weightsupporting andstress resisting means, the elongated body of said tank being of curvedsection and having between the container wall and the jacket stressrings located at intervals along the length of the tank and so securelybonded to the container jacket as also to form reinforcing parts of thesubstantially integral weight-supporting and stress-resisting structuralmeans, transverse contourfitting cross supports being secured to theoutside of said jacket opposite the stress rings, said cross supportsextending between and being secured to the reach bars.

2. A tank truck or trailer according to claim 1 in which the stressrings are also secured to the inner container.

3. A tank truck or trailer according to claim 1 in which the reach barsare provided with contour-fitting flanges engaging the under side of thetank jacket.

4. A double-walled transport tank having the proximal faces of the wallsthereof intimately joined throughout as a unit, whereby when the same ismounted on a wheeled vehicle by connecting its outer surface to thevehicle chassis, localization of stresses, with resulting fatigue,crystallization and cracking, is prevented, said tank including anelongated, outer, tubular wall; an elongated, inner, tubular walltelescoped within the outer wall and having a lesser diameter than theouter wall, presenting a space between the walls surrounding the innerwall, the longitudinal axes of the walls being horizontal, said wallsbeing too light to withstand the structural loads to which the tank isnormally subjected; means closing the ends of said walls; and a core oflightweight insulating material of high compressive strength within saidspace surrounding the inner wall, said core having opposed surfacesengaging and rigidly joined throughout with proximal faces of bothwalls; presenting a substantially integral weight-supporting andstress-resisting means.

5. A double-walled transport tank having the proximal faces of the wallsthereof intimately joined throughout as a unit, whereby when the same ismounted on a wheeled vehicle by connecting its outer surface to thevehicle chassis, localization of stresses, with resulting fatigue,crystallization and cracking, is prevented, said tank including anelongated, outer, tubular wall; an elongated, inner, tubular walltelescoped within the outer wall and having a lesser diameter than theouter wall, presenting a space between the walls surrounding the innerwall, the longitudinal axes of the walls being horizontal, said wallsbeing too light to withstand the structural loads to 6. A double-walledtransport tank having the proximal faces of the walls thereof intimatelyjoined throughout as a unit, whereby when the same is mounted on awheeled vehicle by connecting its outer surface to the vehicle chassis,localization of stresses, with resulting fatigue, crystallization andcracking, is prevented, said tank including an elongated, outer, tubularwall; an elongated, inner, tubular wall telescoped within the outer walland having a lesser diameter than the outer wall, presenting a spacebetween the walls surrounding the inner wall, the longitudinal axes ofthe walls being horizontal, said walls being too light to withstand thestructural loads to which the tank is normally subjected; means closingthe ends of said walls; a plurality of stress rings surrounding theinner wall within said space; means rigidly securing said rings to atleast one of said walls; and a core of light-weight insulating materialof high compressive strength within said space surrounding the innerwall between said rings, said core having opposed surfaces engaging andrigidly joined throughout with proximal faces a of both walls,presenting a substantially integral weightsupporting andstress-resisting means.

7. A double-walled transport tank having the proximal faces of the wallsthereof intimately joined throughout as a unit, whereby when the same ismounted on a wheeled vehicle by connecting its outer surface to thevehicle chassis, localization of stresses, with resulting fatigue,crystallization and cracking, is prevented said tank including anelongated, outer, tubular wall; an elongated, inner, tubular walltelescoped within the outer wall and having a lesser diameter than theouter wall, presenting a space between the walls surrounding the innerwall, the longitudinal axes of the walls being horizontal, said wallsbeing too light to withstand the structural loads to which the tank isnormally subjected; means closing the ends of said walls; a plurality ofstress rings surrounding the inner wall within said space; means rigidlysecuring said rings to at least one of said walls; a core of lightweightinsulating material of high compressive strength within said spacesurrounding the inner wall between said rings, said core having opposedsurfaces engaging and rigidly joined throughout with proximal faces ofboth walls; and means for bonding said surfaces of the core to saidwalls, presenting a substantially integral weight-supporting andstress-resisting means.

8. A double-walled transport tank having the proximal faces of the wallsthereof intimately joined throughout as a unit, whereby when the same ismounted on a wheeled vehicle by connecting its outer surface to thevehicle.

chassis, localization of stresses, with resulting fatigue,crystallization and cracking, is prevented, said tank including anelongated, outer, tubular wall; an elongated, inner, tubular walltelescoped within the outer wall and having a lesser diameter than theouter wall, presenting a space between the walls surrounding the innerwall, the longitudinal axes of the walls being horizontal, said wallsbeing too light to withstand the structural loads to which that tank isnormally subjected; means closing the ends of said walls; a plurality ofstress rings surrounding the inner wall within said space, said ringsengaging both walls; Weld means rigidly securing said rings to both (5said Walls; and a core of lightweight insulating materi of highcompressive strength within said space surrounding the inner wallbetween said rings and engaging the latter, said core having opposedsurfaces engaging and rigidly joined throughout with proximal faces ofboth Walls, presenting a substantially integral weight-supporting andstress-resisting means.

9. A double-walled milk tank having the proximal faces of the wallsthereof intimately joined throughout as a unit, whereby when the same ismounted on a wheeler! vehicle by connecting its outer surface to thevehicle chassis, localization of stresses, with resulting fatigue,crystallization and cracking, is prevented, said tank including anelongated, outer, tubular wall; an elongated, inner, tubular walltelescoped within the outer wall an. having a lesser diameter than theouter wall, presenting a space between the walls surrounding the innerwall, the

longitudinal axes of the walls being horizontal, said walls being toolight to withstand the structural loads to which the tank is normallysubjected; means closing the ends of said walls; a plurality of stressrings surrounding the inner wall within said space, said rings engagingboth walls; weld means rigidly securing said rings to both of saidwalls; a core of lightweight insulating material of high compressivestrength within said space surrounding the inner wall between said ringsand engaging the latter, said core having opposed surfaces engaging andrigidly joined throughout with proximal faces of both Walls; andadhesive means cementing said surfaces of the core to both walls,presenting a substantially integral weightsupporting andstress-resist-means.

References Cited in the file of this patent UNITED STATES PATENTS1,908,684 Buchanan May 16, 1933 2,059,801 Lindsay Nov. 3, 1936 2,160,477Kramer May 30, 1939 2,626,813 Mullen Jan. 27, 1952

